The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 18, 1996
Filed:
May. 12, 1994
Hitoshi Watanabe, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A quantum well type semiconductor laser structure includes light confining layers having an MQB structure including a plurality of semiconductor layers having different compositions laminated alternatingly, the compositions, thicknesses, and number of layers producing an energy barrier higher than the energy barrier inherent to the materials for carriers injected into the active layer, a refractive index distribution in the vicinity of the active layer concentrating the electric field in the active layer, and the quantum barrier layers disposed in contact with the active layer. Therefore, the light confinement in the active layer is increased and the overflow of carriers into the light confinement layer is suppressed whereby the threshold current of the quantum well laser is reduced and the external quantum efficiency is enhanced. A quantum well laser includes, as a barrier layer of an active layer having a multiquantum well structure, a barrier layer having an MQB structure that produces an energy barrier higher than the energy barrier inherent to the materials for carriers injected into the well layer. Therefore, similar effects are obtained.